The instant application should be granted the priority dtaes of Feb. 19, 2008, the filing date of the International patent application PCT/EP2008/001262.
The invention relates to a method for controlling longwall operations in underground coal mining having a face conveyor, at least one extraction machine, and a hydraulic shield support.
The control of longwall operations during face advancing generally is concerned with the best possible exploitation of the provided machine capacities while avoiding shutdowns, an automation of the required control procedures being provided if possible, in order to avoid flawed human decisions. Approaches to automation of the control are in development and/or already in use, such as sensory boundary layer detection/control, learning step methods, recognition and control of the advancing path of the hydraulic supports, automated stepping of the hydraulic supports, and automatic maintenance of a predefined target inclination of the face conveyor.
A problem in the automation of longwall controllers is, inter alia, to ensure that a sufficient height perpendicular to the bed, i.e., a sufficient face opening, is provided in the forward area of the top canopy of each individual shield support frame, in order to ensure the extraction machine travels past undisturbed, because every collision of the extraction machine with the top canopy of the shield support frame as a result of a face opening which is too small results in corresponding operational disturbances and/or also damage of the operating means.
The invention is therefore based on the object of disclosing a method of the type cited at the beginning, which gives notice of a possible collision between the extraction machine and the shield support frame and thus helps to avoid corresponding collisions.